55
9 Supplement
WIKA Operating Instructions - Process pressure transmitter CPT-2x
Reference conditions and influencing variables (according to DIN EN 60770-1)
Reference conditions according to DIN EN 61298-1
Ʋ Temperature
+15 … +25 °C (+59 … +77 °F)
Ʋ Relative humidity
45 … 75 %
Ʋ Air pressure
860 … 1060 mbar/86 … 106 kPa (12.5 … 15.4 psig)
Determination of characteristics
Limit point adjustment according to IEC 61298-2
Characteristic curve
Linear
Reference installation position
upright, diaphragm points downward
Influence of the installation position
< 0.2 mbar/20 Pa (0.003 psig)
Deviation in the current output due to
strong, high-frequency electromagnetic
fields acc. to EN 61326-1
< ±150 µA
Deviation (according to IEC 60770-1)
Specifications refer to the set span. Turn down (TD) is the ratio: nominal measuring range/set span.
Accuracy class
Non-linearity, hysteresis and repeata-
bility with TD 1 : 1 up to 5 : 1
Non-linearity, hysteresis and repeata-
bility with 5 : 1
0.05 %
< 0.05 %
< 0.01 % x TD
0.1 %
< 0.1 %
< 0.02 % x TD
0.2 %
< 0.2 %
< 0.04 % x TD
Influence of the product temperature
Thermal change zero signal and output span through product temperature
Refers to the set span. Turn down (TD) is the ratio: nominal measuring range/set span.
The thermal change of the zero signal and output span corresponds to the temperature error F
T
in
chapter "
Calculation of the total deviation (according to DIN 16086)
".
Basic temperature error F
T
(
F
TBasis
Fig. 32: Basic temperature error F
TBasis
at TD 1 : 1
The basic temperature error in % from the above graphic can increase due to the additional factors,
depending on the measuring cell version (factor FMZ) and the Turn Down (factor FTD). The ad-
ditional factors are listed in the following tables.